JARS v45n3 - Ten Best Dwarfs: An Update

Ten Best Dwarfs: An update
Norman Todd

Reprinted from the Victoria Chapter Newsletter

A few years ago, I wrote about my selection of the best dwarf rhododendrons for the rock garden ( Journal ARS , Vol. 40, No. 3, 1986). Perforce, the choice was made for plants which I had grown and which were more or less easily obtainable.
A little later, Felice Blake, our Australian colleague, wrote about her preferences ( Journal ARS , Vol. 41, No. 3, 1987) and, of course, they were so convincing that I could not but agree with them. Felice has also written about the dwarf form of R. keiskei and its hybrids and this article was published in our book, Rhododendrons on a Western Shore . She has expanded and updated her review of R. keiskei's progeny in an article in the Journal ARS (Vol. 44, No. 1, 1990).
The passage of time - age - makes a great difference to a rhododendron, and probably even more difference to its grower. Albert de Mezey once told me that to grow rhododendrons all that was needed was a physical age of 30 and a longevity of 300. So at best, making choices is a subjective, temporal whimsy, but at least ifs not like picking horses - there are no losers.
Another comforting thing about making a list of good plants is that the species/hybrid debate becomes a total affectation. I don't think the plant itself knows whether it's a species or a hybrid and if it did, I don't think it would care much. I certainly don't, and so this revised list is a mix of both species and hybrids.
I would still rate R. keiskei among the top ten. 'Yaku Fairy' is the name given to the most dwarf, tight forms of this species. It is important to get this form as some other expressions of R. keiskei are by comparison gangling roustabouts. Some dwarf forms are very prostrate, creeping across the ground like Cotoneaster 'Dammeri'. They are good garden-worthy plants but to me not as pleasing as the tiny, bun-shaped ones which have every piece of foliage covered by their pale yellow flowers in April.
As Felice Blake's article attests, R. keiskei has become one of the most popular parents. A couple of these hybrids are now generally available and certainly make the cut for the ten best. Both are Warren Berg hybrids.
These are 'Patty Bee' and 'Ginny Gee'. 'Patty Bee's' other parent is R. fletcherianum . The result is a plant that is larger than R. keiskei but of good rounded form with abundant yellow flowers of a darker hue than that species. Some other R. keiskei hybrids that I now grow have truly deep yellow, daffodil yellow, flowers. 'Golden Bee' ( R. keiskei x R. mekongense var melianthum ) is one. For me, the yellow is too brassy and the foliage is not as good as 'Patty Bee's'. Its sister seedling 'Golden Princess' is another. This is rated a 5/5 by Clint Smith of Benjamin's Nursery. I am prepared to be convinced of this, but as I've only grown it for a couple of years, I'll leave it out of the top ten for now. Another R. keiskei hybrid, this time crossed with R. hanceanum nanum, that is certainly a contender, is 'Princess Anne'. Out of flower, it has the same general effect as 'Patty Bee' but the flowers are paler and some of the foliage goes bronzy in the winter which, for some, is probably a detraction. There is another plant of this cross called 'Shamrock'. This has even paler yellow flowers. I like its pale green flower buds, attractive and unusual, but not sufficiently so to give it top rating.
Still with the yellows, Cox's 'Chikor' and 'Curlew' have to be included in our select few. The former ( R. chryseum x R. ludlowii ) gets the nod from me for being the more choice. The yellow is clear and the flowers match the size of the small leaves. There are two clones with this name. One was given an Award of Merit by the R.H.S. and the other received a First Class Certificate. I'm not sure which form we grow here in Victoria. By contrast, 'Curlew' ( R. ludlowii x R. fletcherianum ) has huge flowers. It has received all the awards including the Cory Cup for the best hybrid on any genus. I find it a little difficult to please; it seems to do better in some shade and because of that, and because of its large flowers, it is only marginally a rock garden plant.
I'll just mention one other pale yellow hybrid that I saw in flower at our convention last year. This is the David Leach hybrid 'Tow Head' ( R. carolinianum , white form, x R. ludlowii ). Coming from Leach, it is very hardy, to -26C, it is claimed. My early impression is that it is good enough to compete with the hybrids already named, but another couple of years will be needed to see if it makes the grade.
That was supposed to be all I was going to say about yellow hybrids, but two more come to mind. The first is 'Wren' ( R. ludlowii x R. keiskei ), another Cox 'Bird' hybrid. So far with us it seems awfully slow, but is a good yellow and Felice Blake calls it "absolutely bewitching". The second is another 'Bird' hybrid - 'Chiffchaff ( R. hanceanum nanum x R. fletcherianum ). Cox says it is not as good a doer as some of his other hybrids but it does well for us and its loose trusses of four to six lemon-yellow flowers are showily refined.
'Ginny Gee' must be one of the most floriferous rhododendron hybrids ever produced. It is R. keiskei crossed with R. racemosum . Its foliage stays dark all year and the pink/white flowers cover it completely in April.
I think R. racemosum is almost at the bottom of my list of favourite rhododendrons. It is leggy, suffers dieback, and has ugly seed capsules that need a Job's patience to remove. It sends up long sappy shoots (these do bear axially the flowers the next year which, blessedly, can be removed to make excellent cut sprays for flower arrangements). These are out of character with the rest of the plant. Its other virtue is that it passes only its good features on to its children. 'Ginny Gee' is a plant you should have in your garden. The Cox's, who have themselves bred not a few of the best dwarf rhododendrons, rate it as one of the best ever raised. The contrast between pink bud and white flower is always effective and is especially so in this plant as it has so many to show. Watch out for the later Warren Berg hybrids 'Wee Bee' and Too Bee'. Both are R. campylogynum , R. keiskei crosses and seem vary promising.
White flowers always seem to attract gardeners and often you will hear them talking about "the rare white form". It is, therefore, a pity that good white flowered rhododendrons are few and far between.
In the small statured plants, Cox's 'Ptarmigan' is not bad, but is a spiky, straggly grower. Kenneth Cox, when he talked at our convention, said it was improved when given a haircut. I haven't found it produces very many flowers; it can't be classed as a luxuriant plant. It reminds me of Daphne blagayana ; its flowers are welcomed, but then forgotten.
In my opinion, the best white flowered dwarf is the species R. anthopogonoides . If you can get your mouth around the name you certainly deserve to grow it. It is rare and it shouldn't be. Peter Cox says there is probably only one plant in cultivation. We have a plant and are now propagating it, especially after seeing a plant with the same name in Warren Berg's garden, thus authenticating it for me. All of the plants in the Anthopogon Series (now called Pogonanthum Section) are so distinctive with a whitish cast to the leaves and their flowers in small tight trusses. Most have vary pleasantly aromatic foliage.
R. anthopogonoides with us as a 10 to 12 year old plant, is about 50 cm high and is nicely, if somewhat openly twigily formed. The flowers are of good substance. It is a better doer for us than R. anthopogon itself. The form of this that we have is called 'Betty Graham' after Sheriff's wife (Sheriff was half of the Ludlow and Sheriff plant hunting team). If you haven't read her account of their trip to Lhasa, etc., in Fletcher's A Quest for Flowers , it's worth searching for it.
'Eider' should probably be included in the top ten. My plant died before I could really appreciate it. It is certainly on the most wanted list.
Still in the Pogonathum Section, I have to include R. trichostomum for which I have a great affection. It is a classy doer and a great plant for bonsai. It has a twisted, spiral growth habit with light ginger-coloured exfoliating bark. The flowers are pink, small and tubular in a tight round truss. They have good substance, lasting about a month or so. It is quite late blooming, for a species - May. There are different forms, some of them named, but probably only available in Britain. It would be worth trying to get them.
I wish I could grow R. campylogynum better than I do. Evan Cox described it as "the rarest and most perky and self-satisfied of all dwarfs". With me it is not as self-satisfied as I would like it to be.
Most of the tiny rhododendrons take a bit more sun than their larger cousins, but I think R. campylogynum likes half-shade and is happiest in moist, but well drained situations. Generally these tiny plants come from high elevations - up to 16,000 feet, and while the light is intense at that altitude, there is not that much of it. Clouds and mist are typical and snow cover lasts many months. And remember, these species get most of their moisture from the monsoons during the summer growing months.
One can go crazy trying to distinguish the different forms of R. campylogynum . It is probably best not to bother overly much - just enjoy them. If it has a very long flower stalk and a nodding bell for a flower cherish it and call it after your daughter or your dog. Flowers are pink, white, yellow, but typically plum coloured and have a unique bloom like a grape on the outside. There is one form, 'Bodnant Red' that is as close to a red as one gets in a lepidote rhododendron.